The pulvinar is a major nucleus in the primate thalamus. It has extensive connections with the visual cortical areas and with the superior colliculus. Electrophysiological studies by the Principal Investigator also sugggest that the pulvinar plays an important role in visual processing and visuomotor integration. It is planned to investiggate the pulvinar's functions in relation to vision using microelectrode recordings both in the immobilized and in the awake, behaving monkey. The immobilized preparation will be used (1) to determine the visutopic organization of the pulvinar, (2) to analyze the visual properties of its neurons, and (3) to determine their dependence on cortical and subcortical sources of input. The behaving animal will be used to examine the correlation between pulvinar neuron activity and eye movements.